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Catalogue XRT results for GRB 090814A

Data were analysed using HEASOFT version 6.29

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Summary Information

RA:15h 58m 26.44sLC breaks:3
Dec:+25° 37′ 52.4′′LC type:Oddball.
Err:1.5′′NH,intr.:5.57×109 cm-2
Gal long:41.872Redshift0.696
Gal lat:48.334Γ1.7
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Jump to: Light curve | Spectra | Compare to other bursts.

If you use any of these data, please cite Evans et al. (2009), which describes how these products were created (see the usage policy for more information).

Light curve

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This light curve comes from the light curve repository (if you use it, please cite Evans et al [2007, 2009]. Flares, marked by cross-hatched regions, are identified automatically, but may have been manually corrected. These are excluded from the fit. Any power-law breaks added to the fit must be required at the 4-σ level (according to an f-test) to be included in the best-fit. Details of all fits attempted are given below the plot. For more information see the light curve fitting documentation.

Fitted light curve of GRB 090814A

Fit Details

Nbreaksχ2dofCommentsImage
0154107Image of this fit
1112105Break required.

(5.68e-06 % probability of chance improvement)
Image of this fit
299.3103Break significance <4-σ
(0.14 % probability of chance improvement)
Image of this fit
384.5101Break required.

(6.58e-04 % probability of chance improvement).
This is the best fit.
Image of this fit
483.199Break significance <4-σ
(44.21 % probability of chance improvement)
Image of this fit
573.997Break significance <4-σ
(1.08 % probability of chance improvement)
Image of this fit

There are no flares ignored from this fit.

The best-fitting light curve has 3 breaks.

Click on the number of breaks in the table to the right to change which fit is plotted above and detailed below.

Currently showing the best fit.

α12.16 (+0.21, -0.34)
Tb,1258 (+24, -40) s
α23.59 (+1.86, -0.64)
Tb,2337 (+46, -43) s
α32.18 (+0.11, -0.10)
Tb,34375 (+1.52 × 103, -1256) s
α40.6 (+0.4, -0.4)

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Spectra

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Spectra have been created for each power-law segment in the best fitting light curve (shown above). Times of flaring have not been removed, however this makes little difference to most spectra (see Fig 7/8c of Evans et al. 2009). For more information see the time-resolved spectroscopy documentation.

Jump to: phase1|phase2|phase3|phase4

phase1 spectrum (T0 + 165 to 257 s)

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Plots to download

WT mode spectrum of GRB 090814A

WT mode. Mean photon arrival: T0+204 s

NH (Galactic)5.88 × 1020 cm-2
NH (intrinsic)3.3 (+0.7, -0.7) × 1021 cm-2
z of absorber0.696
Photon index2.77 (+0.13, -0.12)
Flux (0.3-10 keV)
(Observed)
6.3 (+0.3, -0.3) × 10-10 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.186 (+0.115, -0.094) × 10-9 erg cm-2 s-1
Counts to flux (obs)2.42 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.56 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
380.13 (382)
Spectrum exposure92 s

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phase2 spectrum (T0 + 257 to 336 s)

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WT mode spectrum of GRB 090814A

WT mode. Mean photon arrival: T0+290 s

NH (Galactic)5.88 × 1020 cm-2
NH (intrinsic)6.8 (+10.1, -6.8) × 1020 cm-2
z of absorber0.696
Photon index2.48 (+0.21, -0.20)
Flux (0.3-10 keV)
(Observed)
2.53 (+0.25, -0.23) × 10-10 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
3.4 (+0.4, -0.3) × 10-10 erg cm-2 s-1
Counts to flux (obs)2.54 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.45 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
276.22 (266)
Spectrum exposure78 s

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phase3 spectrum (T0 + 336 to 2554 s)

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WT and PC mode spectra of GRB 090814A

WT mode. Mean photon arrival: T0+378 s

NH (Galactic)5.88 × 1020 cm-2
NH (intrinsic)0 (+5.21 × 1020, -0) cm-2
z of absorber0.696
Photon index2.51 (+0.17, -0.14)
Flux (0.3-10 keV)
(Observed)
1.31 (+0.14, -0.12) × 10-10 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.68 (+0.15, -0.15) × 10-10 erg cm-2 s-1
Counts to flux (obs)2.53 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)3.25 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
164.25 (194)
Spectrum exposure87 s

PC mode. Mean photon arrival: T0+1057 s

NH (Galactic)5.88 × 1020 cm-2
NH (intrinsic)0 (+2.46 × 1020, -0) cm-2
z of absorber0.696
Photon index1.662 (+0.120, -0.093)
Flux (0.3-10 keV)
(Observed)
1.71 (+0.20, -0.14) × 10-11 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
1.86 (+0.20, -0.15) × 10-11 erg cm-2 s-1
Counts to flux (obs)3.93 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.29 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
219.92 (257)
Spectrum exposure2.1 ks

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phase4 spectrum (T0 + 5685 to 417992 s)

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PC mode spectrum of GRB 090814A

PC mode. Mean photon arrival: T0+54124 s

NH (Galactic)5.88 × 1020 cm-2
NH (intrinsic)2.7 (+7.6, -2.7) × 1021 cm-2
z of absorber0.696
Photon index2.6 (+1.0, -0.7)
Flux (0.3-10 keV)
(Observed)
4.1 (+1.9, -1.4) × 10-14 erg cm-2 s-1
Flux (0.3-10 keV)
(Unabsorbed)
6.9 (+8.3, -2.1) × 10-14 erg cm-2 s-1
Counts to flux (obs)2.71 × 10-11 erg cm-2 ct-1
Counts to flux (unabs)4.56 × 10-11 erg cm-2 ct-1
W-stat (dof)
What's this?
68.02 (67)
Spectrum exposure42.6 ks

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Comparison with other bursts

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Parameter distributions

The plots below show the probability density functions of the temporal and time-averaged spectral parameters for all GRBs, with the data for GRB 090814A shown on in colour. Click the images for larger versions.

For all plots, the solid vertical lines mark the values for this GRB, and the dashed lines the 1-σ uncertainties. For α and Tb, the colour changes for each phase. For the spectral parameters, the WT fits are shown in blue and the PC in red. These figures correspond to Figs. 5,6, 7a and 8a of Evans et al. (2009). See the PDF documentation for more information.

Temporal indicesBreak TimesNHSpectral indices
Comparison of decay indices Comparison of light curve break times Comparison of intrinsic column densities Comparison of spectral energy indices

Closure Relationships

The plots below show (α, β) scatter plots for each of the different types/phases of light curves (see light-curve types), since GRB 090814A is of type, "Oddball," which has no scatter plots of its own. GRB 090814A is shown in colour, with each light curve phase, or XRT mode marked by a different colour. α and β are the temporal and spectral energy power-law indices respectively. The shaded regions mark those allowed by the standard closure relationships. These figures correspond to Fig. 10 of Evans et al. (2009). See the closure relationship documentation for more information.

No break
Comparison of nobreak closures
One-break, steep first
Steep phase
One-break, steep first
Shallow phase
Comparison of One-break, steep first, steep phase closuresComparison of One-break, steep first, shallow phase closures
One-break, shallow first
Shallow phase
One-break, shallow first
Steep phase
Comparison of One-break, shallow first, shallow phase closuresComparison of One-break, shallow first, steep phase closures
Canonical
Steep phase
Canonical
Plateau
Canonical
'Normal'
Canonical
Post jet-break
Comparison of Canonical, steep phase closuresComparison of Canonical, plateau phase closuresComparison of Canonical, normal phase closuresComparison of Canonical, post jet-break phase closures

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